Illinois state highway system Illinois Tollway system

Interstate 474 (I-474) is an Interstate Highway loop route that provides a southern bypass around the north central Illinois city of Peoria. I-474's parent interstate is I-74. As the first digit of the interstate's number is even, it follows the established convention of providing a loop around a city. Interstate 474 is 14.88 miles (23.95 km) long. I-474 is the highest numbered route in the state of Illinois.

Interstate 474 is a modern, Interstate-standard four-lane freeway for its entire length. Prior to 2006, thru truck traffic on I-74 was instructed to use I-474. This is because prior to its 2004-2007 reconstruction, Interstate 74 was significantly below Interstate standard, having numerous 15 mph (24 km/h) onramps and offramps, extremely short merging space for onramps (some less than 500 feet (152 m) in length), and a 50 mph (80 km/h) speed limit through downtown Peoria.

The Illinois Route 116 access interchange at Maxwell Road has been indicated as the eastern terminus for the Quincy to Peoria expressway now known as the Illinois Route 336 project.

The western terminus of the interstate is at I-74, exit #87A. The eastern terminus of the route is at I-74, exit #100. North of the western terminus, the route continues as Illinois Route 6 with a new series of exit numbers.

I-474 was constructed through the mid 1970s. The now-named Shade-Lohmann Bridge was erected in 1973. During that year, $30.1 million was allocated for acquisition of right-of-way, grading work and overpass/bridge construction across the whole length of the highway.